Blindmate heat sink assembly

ABSTRACT

A heat sink and processor assembly that can be easily installed and uninstalled from a circuit board without tools. One preferred embodiment of the heat sink assembly comprises a heat sink component, an alignment cage attached to the base of the heat sink and having an attachment point for releasably attaching a processor. The heat sink assembly further comprises a plurality of alignment pins and alignment tabs that are affixed to the base of the heat sink and interface with a specially designed socket and circuit board so as to align the mating components. The processor chip is installed onto the heat sink and then the combined assembly is installed onto a circuit board mounted socket. The alignment mechanisms provide a method for installing a processor without using tools or having to manually align the processor pins to the socket receptacles.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] The present invention generally relates to methods and apparatusfor installing heat sinks and processors to a circuit board. Moreparticularly, the present invention relates to methods and apparatus forattaching a processor to a heat sink to form an assembly that can thenbe attached to a circuit board without any tools or risk of damage tothe processor.

[0005] 2. Background of the Invention

[0006] Conventionally, a processor is mounted in a socket on a printedcircuit board that includes a plurality of integrated circuits securedthereto. Heat dissipation affects the operation of the processor andthus it is desirable to have a highly effective heat sink for theprocessor. These types of heat sinks are often attached to the processorby way of a thermal interface, which serves to attach the heat sink tothe processor and provide a path for thermal energy. In high powerprocessor applications, the heat sink required for a given processor mayhave a much larger footprint than the processor itself.

[0007] The processor is first installed into a socket on the circuitboard and retained in place by a lock mechanism that is often integralto the socket. Most processors are installed onto a socket by hand andit is up to the installer to ensure proper alignment of the processorpins with the holes on the socket. Because the pins on a processor areoften very small and fragile, it is not uncommon to damage one or morepins during installation. If the pins of the processor are damaged theymust be repaired and the processor will likely have to be replaced.

[0008] Once the processor is installed, the heat sink is then affixed tothe top of the processor by the thermal interface material. The size ofthe heat sink may be large enough to prevent unlocking and removing ofthe processor while the heat sink is installed. Therefore, the heat sinkmust be removed from the processor before the processor can be removedfrom the socket. There exists no method or apparatus in the prior art toeasily separate the heat sink from the processor once the thermalinterface has been heated. Often this removal is performed using bruteforce, often resulting in damage to the processor during the removalprocess.

[0009] Therefore, there remains a need in the art for methods andapparatus that allow for processors and heat sinks to be installed anduninstalled from a circuit board without risking damage to theprocessor. It is also desirable to have a processor and heat sinkassembly that can be installed and uninstalled without tools and withoutrelying on the steady hand of a technician to prevent damage to theprocessor chip. The preferred embodiments of the present inventiondescribed below overcome these and other deficiencies of the prior artwhile focusing on these needs.

BRIEF SUMMARY OF THE PREFERRED EMBODIMENTS OF THE INVENTION

[0010] The preferred embodiments of the present invention overcome thedeficiencies of the prior art noted above, by providing a heat sinkprocessor assembly that can be easily installed and uninstalled from acircuit board configured to accept the assembly. Accordingly, onepreferred embodiment of the heat sink assembly comprises a heat sinkcomponent and an alignment cage that is attached to the base of the heatsink. The heat sink assembly further comprises a plurality of alignmentpins affixed to the base of the heat sink that align to features builtinto the circuit board. The alignment cage further comprises anattachment point for releasably attaching a processor with sufficientstrength to maintain contact between the processor and the heat sink butalso allowing the processor to “float” in order to properly interfacewith mating holes on a socket, given all the tolerance variationspossible in the system. The alignment cage comprises features that,along with the pins on the processor, interface with a speciallydesigned socket to properly align and seat the processor chip. Thus, theprocessor, heat sink assembly, and socket all comprise features thatwork together to allow easy engagement and disengagement of theprocessor without tools and without having to pry the heat sink from theprocessor.

[0011] Once the processor is attached to the alignment cage, the heatsink assembly is prepared for installation onto the circuit board. Thecircuit board has a plurality of holes arranged to accept the alignmentpins. Inserting the alignment pins into the chamfered holes on thecircuit board provides a rough alignment of the processor to a socketalso mounted to the circuit board. As the alignment pins are insertedinto the holes, the alignment cage interacts with the socket providingan intermediate alignment between the processor and the socket. Theintermediate alignment provides an alignment that is within thetolerances that allow the inherent alignment features of the processorand the socket to provide the final alignment of the processor pins withthe chamfered receiving holes on the socket. Once the processor is fullyengaged with the socket, the processor is electrically coupled to thesocket by actuating a socket locking lever that is extended beyond theheat sink volume. The heat sink and socket assembly can be uninstalledby reversing this procedure.

[0012] Accordingly, this particular embodiment of the present inventionprovides a heat sink and processor assembly that can be installed onto acircuit board with a socket that comprises unique features that allowfor installation the neither requires tools nor damages the processor.Therefore, the embodiments of the present invention provide a heatsink/processor assembly and circuit board and socket arrangement thatdecrease the difficulty and costs of installing and maintaining heatsinks and processors.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] For a detailed description of the preferred embodiments of theinvention, reference will now be made to the accompanying drawings inwhich:

[0014]FIG. 1 is an isometric view of one embodiment of the heat sinkassembly without a processor installed;

[0015]FIG. 2 is an isometric view of one embodiment of the heat sinkassembly with a processor installed;

[0016]FIG. 3 is a plan view of one embodiment of an alignment cage andalignment pins;

[0017]FIG. 4 is a plan view of one embodiment of a socket installed on acircuit board;

[0018]FIG. 5 is a schematic elevation view of a heat sink assemblyinterfacing with a socket and circuit board in a first position;

[0019]FIG. 6 is a schematic elevation view of a heat sink assemblyinterfacing with a socket and circuit board in a second position;

[0020]FIG. 7 is a schematic elevation view of a heat sink assemblyinterfacing with a socket and circuit board in a third position;

[0021]FIG. 8 is a schematic elevation view of a heat sink assemblyinterfacing with a socket and circuit board in a fully engaged position;and

[0022]FIG. 9 is a side view of the socket.

NOTATION AND NOMENCLATURE

[0023] Certain terms are used throughout the following description andclaims to refer to particular system components. As one skilled in theart will appreciate, computer companies may refer to a component bydifferent names. This document does not intend to distinguish betweencomponents that differ in name but not function. In the followingdiscussion and in the claims, the terms “including” and “comprising” areused in an open-ended fashion, and thus should be interpreted to mean“including, but not limited to . . . ”. Assembly is used to define theassembly of a heat sink and a processor chip. Board is used to refer toan integrated circuit board.

[0024] In the description that follows, like parts are marked throughoutthe specification and drawings with the same reference numerals,respectively. The drawing figures are not necessarily to scale. Certainfeatures of the invention may be shown exaggerated in scale or insomewhat schematic form and some details of conventional elements maynot be shown in the interest of clarity and conciseness.

[0025] In order to fully describe the preferred embodiments of thepresent invention, reference will be made throughout this description toa heat sink and processor assembly that shows a typical 603 pinprocessor chip, but the concepts described herein are applicable toother types of computers and integrated circuit chips, as well asnon-computer applications. Embodiments of the present invention may findparticular use with integrated circuit chips other than processors aswell as other components that interface by way of a multi-pinconnection. The present invention is susceptible to embodiments ofdifferent forms. There are shown in the drawings, and herein will bedescribed in detail, specific embodiments of the present invention withthe understanding that the present disclosure is to be considered anexemplification of the principles of the invention, and is not intendedto limit the invention to that illustrated and described herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Referring now to FIGS. 1 and 2, a heat sink assembly 10,constructed in accordance with the preferred embodiment, comprises analignment cage 12, and a plurality of alignment pins 14 attached to aheat sink 10. The alignment cage 12 comprises a plurality of locatingtabs 16, 18 that surround a receptacle 24 sized to receive a processorchip 26. As shown in FIG. 2, receptacle 24 comprises a pair of clips 20,or some other mechanism for retaining the processor chip 26 in place. Asbest seen in FIG. 1, receptacle 24 is preferably adapted to receive athermal interface film 22 to enhance the thermal connection between theprocessor chip 26 and the heat sink 11. Processor chip 26 is installedwith pins 28 facing away from the heat sink 11 and once installed isready for installation onto a circuit board.

[0027]FIG. 3 and FIG. 4 depict, respectively, schematic representationsof the interfacing portions of heat sink assembly 10 with a processor 26installed and the corresponding interfacing portions of circuit board 30and chip socket 34. Circuit board 30 has a plurality of holes 32 thatare sized and spaced to accommodate alignment pins 14. Alignment pins 14entering holes 32 serves as the initial gross alignment of the processorchip 26 and the socket 34. As the heat sink assembly 10 is lowered,locating tabs 18 interface with corresponding slots 36 integrallyconstructed into socket 34 and tabs 16 are spaced so as to fit alongedges 38, 40 of socket 34. The interaction of locating tabs 16,18 andthe socket 34 ensures that processor pins 28 will enter thecorresponding receptacles 42 built into socket 34. In addition, clips 20have clearance slots 35 built into socket 34. Once processor 26 is fullyengaged into socket 34, locking lever 44 is actuated, which locks theprocessor in place and couples the processor to the circuit board.Locking lever 44 located at the end of an extended arm 46 so that it canbe accessed when the heat sink assembly 10 is installed.

[0028] FIGS. 5-8 depict the sequence of events that occur as assembly 10is installed onto circuit board 30. FIG. 5 shows assembly 10 positionedjust prior to engaging circuit board 30. Alignment pins 14 arepositioned by the used to align with holes 32 located on circuit board30. Holes 32 preferably have a chamfered opening 48 that, along withchamfered head 50 of pin 14, directs each pin 14 into its correspondinghole 32. Assembly 10 preferably comprises at least two alignment pins 14to positively locate the assembly 10 on the circuit board 30. It is alsopreferred that the alignment pins 14 are arranged so that the assembly10 can only be installed in one position relative to board 30. This ispreferably accomplished by using three alignment pins 14, which allowassembly 10 to be installed in only one position and provide a stablebase for the assembly 10.

[0029]FIG. 6 depicts assembly 10 as it is aligned with board 30 and asthe alignment cage 12 begins to interface with socket 34. Alignment tabs18 fit into slots 36 on socket 34 to position assembly 10 in onedirection, while positioning in the perpendicular direction iscontrolled by alignment tabs 16 contacting the outside edges of socket34. Alignment tabs 16,18 work to refine the alignment of assembly 10 tosocket 34 and place the processor 26 in position to properly engage thesocket. Cage 12, by way of clips 20, retains the processor 26 butpreferably provides the compliance to allow the processor to easilyinterface with socket 34. It is preferred that the alignment tabs 16,18serve to further refine the alignment of processor 26 with socket 34 toa position to enable the processor pins 28 to easily engage receptacles42 without damaging the pins.

[0030]FIG. 7 shows the assembly 10 as processor pins 28 are aligningwith mounting holes 42. Each mounting hole 42 has a chamfered entrance43 that combined with the chamfered, or pointed, end 29 of pin 28 allowsthe pin to smoothly enter the mounting hole.

[0031]FIG. 8 shows the assembly 10 fully assembled onto board 30 andsocket 34. In this position the processor is fully seated on socket 34,and the socket can be moved to the closed position. In the fully seatedposition, as shown in FIG. 7, alignment pins 14 preferably penetratethrough board 30 and have an area of reduced diameter 50 onto which aclamp (not shown) can be affixed to secure heat sink assembly 10 toboard 30.

[0032]FIG. 9 shows an end view of socket 34 with locking lever 44 shownin both an open position 46 and a closed position 48. In both open 46and closed 48 positions, locking lever 44 is elevated above, and at anangle to, board 30. This provides clearance beneath locking lever 44 forother components to be mounted to board 30 and makes it easier for auser to manually actuate the lever. Referring back to FIG. 1, cage 12preferably comprises a tab 52 located at one corner of the cage. Theclosed position 48 of locking lever 44 is arranged so as to interferewith tab 52 and prevent insertion of processor 26 into socket 34 if itis closed.

[0033] In an alternative embodiment, the position of the alignment pinsand the holes may be reversed with the pins being mounted on the boardand the holes being in the heat sink assembly. This arrangement may beused if there is limited access to the underside of the board. Otherembodiments may include sockets that provide all alignment featuresnecessary to seat the chip, therefore eliminating any alignment featureson the board, or heat sink and processor assemblies that are used toinstall multiple chips simultaneously. It is also contemplated thatthere are many different arrangements of alignment pins and alignmenttabs that will perform identical functions to the embodiments describedabove.

[0034] It is preferred that the heat sink and the alignment pins beconstructed of metal. The alignment cage and socket are preferablyconstructed from a thermoplastic material such as is common in computercomponents.

[0035] Therefore the preferred embodiments of the present inventiondescribed above provide a method and apparatus for simultaneouslyinstalling a processor chip and a heat sink to a circuit board withoutneeding any tools. The embodiments of the present invention provideapparatus that ensure the proper engagement of the processor chip to asocket, therefore preventing any damage to the chip during theinstallation sequence. The above described embodiments also provide anapparatus that limits the installation errors that can be made by a userby providing parts that only interface in one method and can not beinstalled improperly. Therefore, the embodiments of the presentinvention decrease the costs of installing and maintaining highperformance processor chips that require very large heat sinks.

[0036] The above discussion is meant to be illustrative of theprinciples and various embodiments of the present invention. Numerousvariations and modifications will become apparent to those skilled inthe art once the above disclosure is fully appreciated. For example, arail designed in accordance with the present invention could be used ina non-computer environment as a drawer slide or other such device. It isintended that the following claims be interpreted to embrace all suchvariations and modifications.

What is claimed is:
 1. A computer assembly comprising: an integratedcircuit chip; a heat sink; an alignment cage attached to said heat sinkand capable of receiving said integrated circuit chip; a circuit board;and a socket mounted to said circuit board and adapted to receive saidintegrated circuit chip, wherein said alignment cage comprises analignment tab that aligns said alignment cage to said socket.
 2. Thecomputer assembly of claim 1, further comprising an alignment pinattached to said heat sink and a receptacle on said circuit board forreceiving said alignment pin.
 3. The computer assembly of claim 1,wherein said socket has a locking lever that is actuatable when saidheat sink is installed.
 4. The computer assembly of claim 1, whereinsaid heat sink prevents observation of an interface between said chipand said socket.
 5. The computer assembly of claim 1, wherein said chipis attached to said alignment cage before being installed on saidsocket.
 6. A method of installing an integrated circuit chip and heatsink onto a socket mounted to a circuit board, the method comprisingsteps: (1) attaching the chip to an alignment cage mounted to the heatsink; (2) inserting alignment pins that are mounted to the heat sinkinto receptacles located on the circuit board; (3) inserting the chipinto the socket; and (4) locking the chip onto the socket.
 7. The methodof claim 6, further comprising interfacing the alignment cage to thesocket after step (2) but before step (3).
 8. The method of claim 6,wherein the method is performed without any tools.
 9. The method ofclaim 6, wherein observation of step (3) is obscured by the heat sink.10. A heat sink assembly comprising: a heat sink member having a base;an alignment cage attached to the base of said heat sink member; and aplurality of alignment pins attached to the base of said heat sinkmember.
 11. The assembly of claim 10, further comprising an integratedcircuit chip affixed to said alignment cage.
 12. The assembly of claim10, wherein said alignment cage comprises a plurality of alignment tabs.13. A integrated circuit chip socket having an open and closed position,the socket comprising: an interface for coupling a integrated circuitchip to a circuit board; and a plurality of slots disposed around theperimeter of said interface and providing an interface surface foralignment of a heat sink.
 14. The socket of claim 13, furthercomprising; an extended portion; and a locking arm mounted to saidextending portion for actuating the socket between the open and closedpositions.
 15. A computer assembly comprising: an integrated circuitchip; a heat sink assembly attached to said chip; a circuit board; asocket adapted to receive said chip and attached to said circuit board;a means for aligning said heat sink to said circuit board; and a meansfor aligning said heat sink to said socket.
 16. The assembly of claim15, further comprising a means for aligning said chip to said socket.17. The assembly of claim 15, wherein said means for aligning said heatsink to said circuit board comprises a plurality of pins interfacingwith a corresponding plurality of holes.
 18. The assembly of claim 15,wherein said means for aligning said heat sink to said socket comprisesa plurality of tabs interfacing with a corresponding plurality of slots.19. A method for removing an integrated circuit chip and heat sink froma circuit board comprising: actuating a locking lever on a socket to anopen position; lifting the heat sink off of the circuit board; andremoving the chip from the heat sink.
 20. The method of claim 19,wherein the chip is removed from the heat sink by releasing one or moreclips.
 21. A computer assembly comprising: a component having multiplepins; a heat sink; an alignment cage attached to said heat sink andcapable of receiving said component; a circuit board; and a socketmounted to said circuit board and adapted to receive the pins of saidcomponent, wherein said alignment cage comprises an alignment tab thataligns said alignment cage to said socket.
 22. The computer assembly ofclaim 21, further comprising an alignment pin attached to said heat sinkand a receptacle on said circuit board for receiving said alignment pin.23. The computer assembly of claim 21, wherein said socket has a lockinglever that is actuatable when said heat sink is installed.
 24. Thecomputer assembly of claim 21, wherein said heat sink preventsobservation of an interface between said component and said socket. 25.The computer assembly of claim 21, wherein said component is attached tosaid alignment cage before being installed on said socket.
 26. A methodof installing a multi-pin electrical component and heat sink onto asocket mounted to a circuit board, the method comprising steps: (1)attaching the component to an alignment cage mounted to the heat sink;(2) inserting alignment members that are mounted to the heat sink intoreceptacles located on the circuit board; (3) inserting the componentinto the socket; and (4) locking the component onto the socket.
 27. Themethod of claim 26, further comprising interfacing the alignment cage tothe socket after step (2) but before step (3).
 28. The method of claim26, wherein the method is performed without any tools.
 29. The method ofclaim 26, wherein observation of step (3) is obscured by the heat sink.